An LED is a small light source with low power consumption. A white LED has attracted attention as an illumination device alternative to an incandescent lamp and a fluorescent lamp. In addition, an ultraviolet LED has attracted attention as an ultraviolet light source in applications including sterilization, air cleaning, cancer treatment, and resin curing.
In order to effectively utilize light emitted from a light emitting body in a device including the LED, a light reflective substrate having a high light reflectance is required.
For example, alumina ceramic having a relatively high light reflectance, or alumina ceramic having formed thereon a light reflective film formed of a metal is used as the light reflective substrate. However, such light reflective substrate cannot provide a sufficient quantity of light. Therefore, a further increase in light reflectance is required for the light reflective substrate.